As the integration level of semiconductor devices continuously increases, critical dimensions of a static random access memory (SRAM) continues decreasing.
A conventional SRAM cell usually includes a 6T structure. Such SRAM cell having 6T structure usually includes a memory unit and two read/write units. The memory unit includes two pull-up transistors and two pull-down transistors. In the memory unit, the two pull-up transistors connect to word lines and the two pull-down transistors connect to ground lines. The memory unit includes two storage nodes and two opening nodes, for storing 1 or 0 signal. The two read/write units in the SRAM cell are two transmission transistors. One end of each transmission transistor is connected to a storage node and an opening node of the memory unit respectively. The other end of each transmission transistor is connected to a bit line for reading/writing on the memory unit respectively.
However, the fabrication of SRAM becomes more difficult due to the reduction of the critical dimensions of the SRAM. The disclosed devices and methods are directed to at least partially alleviate one or more problems set forth above and to solve other problems in the art.